Yazar "Cengiz, E." seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • [ X ]
    Öğe
    Determination of the Mass Attenuation Coefficient, Effective Atomic Number and Electron Density for Nano Manganese Hydroxyapatite by using 778-1457 keV Gamma Rays
    (Ankara Üniversitesi, 2018) Köksal, O.k.; Cengiz, E.; Apaydın, G.; Tozar, A.; Karahan, İ. H.
    In this study, Nano Manganese substituted hydroxyapatite artificial bone powders (nMnHAp) have been investigated by means of mass attenuation coefficients, effective atomic numbers and electron densities experimentally. The samples were excited with using 778 keV, 964 keV, 1085 keV, 1111 keV, 1408 keV and 1457 keV gamma photons from Europium-152 (Eu152).The gamma photons from the source were counted by using gamma spectroscopy, a High Purity Germanium (HPGe) detector. The mass attenuation coefficients of the hydroxyapatites artificial bone powders (including hydroxyapatite without any substituted metal and real bone powder) were compared with each other. This study has been dealt with as a guide to medical field. Also the results have been evaluated in terms of the electron density and effectice atomic number.
  • [ X ]
    Öğe
    Evaluation of theoretical, semi-empirical, and empirical approaches for determining K-shell absorption parameters for elements with Z=18-100
    (Pergamon-Elsevier Science Ltd, 2026) Hamied, I.; Kahoul, A.; Cengiz, E.; Marques, J. P.; Daoudi, S.; Parente, F.; Sampaio, J. M.
    This study presents a comprehensive evaluation of K-shell absorption parameters for elements with atomic numbers ranging from 18 to 100. The focus is on key parameters such as the absorption jump ratio, the absorption jump factor, the Davisson-Kirchner ratio, and the oscillator strength. The accuracy and reliability of these parameters are critically assessed using analytical, experimental, and theoretical approaches. Experimental values are compiled based on a thorough review of current literature, while theoretical values are calculated using established computational models such as XCOM and FFAST. Analytical estimations are derived through a combination of empirical and semi-empirical methods, aiming to explain systematic trends and correlations between absorption properties and atomic numbers. The findings provide valuable insights into K-shell absorption mechanisms and underscore the importance of accurate parameterization in advancing the understanding of X-ray absorption physics.
  • [ X ]
    Öğe
    Investigation of gamma radiation shielding properties of hafnium dioxide thin films prepared at different molarities with using 14.9, 22.1, 32.1, 41.5 and 59.5 keV energies
    (Pergamon-Elsevier Science Ltd, 2026) Kanmaz, I.; Kaksal, O. K.; Apaydin, G.; Tomakin, M.; Cengiz, E.
    Effective shielding against gamma radiation is essential in sensitive domains such as microelectronics, aerospace technology, and radiation detection systems. In this regard, thin-film technologies are considered to provide effective and appropriate protection in microscale systems to alleviate the detrimental effects of gamma radiation. This study investigates the fabrication of HfO2 thin films at five distinct molarities via a spin-coating technique, a modification of the sol-gel method. The radiation shielding parameters, such as linear attenuation coefficient (LAC), mass attenuation coefficient (MAC), tenth value layer (TVL), mean free path (MFP), and half value layer (HVL), were thoroughly analysed. This study investigated the effectiveness of different materials in shielding photons emitted from Yttrium K alpha (14.9 keV), Silver K alpha (22.1 keV), Barium K alpha (32.1 keV), Europium K alpha (41.5 keV), and Americium-241 K alpha (59.5 keV) sources. The radiation shielding parameters for the Americium241 radioactive annular gamma source, were meticulously examined using the secondary induced radiation attenuation method, which facilitated the extraction of multiple energies from a singular source while preserving the identical geometry. This experiment employed a photon-counting detection system characterized by a resolution of 150 eV at an energy level of 5.95 keV. The attenuation results of thin hafnium dioxide films with different thickness and molarity ratios were examined in this study demonstrate their potential as effective attenuation materials at suitable thicknesses. The results indicated that increased molarity significantly affected the thickness of thin films, and the attenuation properties improved with higher molarity.